Strain compensation in lattice mismatched short-period superlattices

✍ Scribed by J.S. Nelson; L.R. Dawson; C.Y. Fong; L.A. Hemstreet

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 147 KB
• Volume: 23
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1996.0437

✦ Synopsis

The electronic properties of [001] (AlAs) n -(AlSb) n short-period strained-layersuperlattices (SPSLS) lattice matched to InP, for n ≤ 4, have been calculated with a firstprinciples self-consistent pseudopotential method. The layer dependence of the interplanar relaxations, direct and indirect band gaps, and spin-orbit and valence band strain splittings are studied. Evolution of the superlattice states from the bulk constituents is discussed in terms of wavefunction mixing and band repulsion due to zone-folding. The band structures of the SPSLSs are compared with a disordered alloy of AlAs 0.5 Sb 0.5 represented by the special quasirandom structure. We find that continuum models of the total valence band splitting (strain and spin-orbit) do not accurately represent the electronic structure of lattice mismatched SPSLS, due to strong mixing of the heavy-and light-hole states across the interface.